Answer:
x = 4
Step-by-step explanation:
x + 4(x+5) = 40 (Given)
x + 4x + 20 = 40 (Distribute the 4 into the x and 5)
5x + 20 = 40 (Add like terms)
5x = 20 (Subtract 20 on both sides)
x = 4 (Divide 5 on both sides)
<h3>
Answer:</h3>
(x, y) = (7, -5)
<h3>
Step-by-step explanation:</h3>
It generally works well to follow directions.
The matrix of coefficients is ...
![\left[\begin{array}{cc}2&4\\-5&3\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D2%264%5C%5C-5%263%5Cend%7Barray%7D%5Cright%5D)
Its inverse is the transpose of the cofactor matrix, divided by the determinant. That is ...
![\dfrac{1}{26}\left[\begin{array}{ccc}3&-4\\5&2\end{array}\right]](https://tex.z-dn.net/?f=%5Cdfrac%7B1%7D%7B26%7D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D3%26-4%5C%5C5%262%5Cend%7Barray%7D%5Cright%5D)
So the solution is the product of this and the vector of constants [-6, -50]. That product is ...
... x = (3·(-6) +(-4)(-50))/26 = 7
... y = (5·(-6) +2·(-50))/26 = -5
The solution using inverse matrices is ...
... (x, y) = (7, -5)
Answer:
9 Sides
Step-by-step explanation:
According to the Question,
- Given That, The sum of the interior angles(s), in an n-sided polygon can be determined using the formula s=180(n−2), where n is the number of sides
Therefore, The sides do a polygon have if the sum of the interior angles is 1,260°.
Put The Values in Formula, we get
1260=180(n−2)
n-2 = 7
n=9 (9 Sides)
-2. or otherwise put as -2/1
Answer:
A construction worker may use trigonometry when building the roof of a house. They may have to calculate the right angle that hypotenuse must sit at so water doesn't build up on the roof and cause leaks.
(this may be more of an architect's job, as they are the ones that design the houses)
or
An air traffic controller may use trigonometry to find how long it will take an airplane to land/how far the airplane is from the ground while it is in the sky (hypotenuse), based on its height from the ground (opposite) and the distance away from the runway it is (adjacent). They can also calculate the angle of elevation of the airplane from the tower they work in.
